Synthetic resin



Patented Dec. 14, 1937 4 2,101,948

UNITED STATES PATENT OFFICE 2,101,948 SYNTHETIC RESIN Felix Lauter, Evanston, Ill., assignor to Sealkote Corporation, Chicago, 111., a corporation of Delaware No Drawing. Application December I, 1935, Serial No. 53,430

4 Claims. (01. 260-8) My invention relates to a synthetic resin of the until a temperature not higher than 245 C. is glycerine-phthalic acid type; and the primary obreached. ject of the invention is to provide a synthetic The lactic acid is used merely as a cataiyzer resin which will remain in solution with cellulose and in such small quantities,- say from of a acetate for the production of a stable and trans-- mol. to of a mol. that its presence in the final 5 parent film. product is inappreciable.

Resinous products formed by reacting polybasic The resin so produced has a melting point of aromatic acids and polyhydric alcohols are about 73 C. and acid numbers between 65 and 73 known. Resins of this type containing polybasic and is consequently soft and plastic.

10 aliphatic acids such as tartaric, maleic and suc- In place of using phthalic anhydride one could 10 cinic are also known. use phthalic acid.

Arsem in his United States Patent No. 1,098,776 For glycerine it would be possible to use glycol, describes a reaction product of 1 mol. of phthalic a s Or Oth Polyalcohols, althoughswhere anhydride, 1 mol. of giycerine and 1 mol. of succolorless solution is desired, glycerine is probably 5 cinic acid. The patent also describes a reaction the only practical substance of this class. product of 1 mol. of phthalic anhydride, 1 mol. of I claim: glycerine and 1 mol. of lactic acid, claiming for 1. Method of pro n a r in us r action the last product a flow point of 64 0. and stickiproduct which will remain in solution with celluness, but that if the proportion of lactic acid were 1058 acetate r the Production of a Stable and decreased the proportion of phthalic anhydride transparent film and s p a a y water white 20' increased, the flow point would b rai d, a d by and when dissolved in acetone or ethyl acetate or heating the material hard n d, both is miscible in all proportions with cellulose It is a fact, however, that all condensation acetate that Comprises heating an admixture products of the prior art if efiort be made to comabout 2 6 parts by Weight of phthalic anhydride 5 bine or mix th ith cellulose t t have and about 184 parts of glycerine in an air tight advantages such as the throwing out of the cellucontainer equipped with a sealed reflux condenser lose acetate or the production of a blush on the agitating the mixture when it reaches a fluid mm obscuring its transparency state and then adding about 2 parts of lactic acid I have now found that by using a monobasic as a catalyzing agent, heating the mass for about aliphatic acid, such as lactic acid, as a catalyzer, 2 hours at a temperature not higher than 30 in conjunction with phthalic anhydride and glycand concentrating and distilling in an open vessel erine in proportions of ,6 of a mol. of lactic acid at a temperature not to exceed to 1 mol. of glycerine, under conditions which Method of Producing resinous reaction bring about the elimination of oxygen during the product which will remain in solution with cellureaction, a material is obtained which is prac lose acetate for the production of a stable and 35 tically water white, and when dissolved in acetone transparent film and is practically water white or ethyl acetate, or both, is miscible in and when dissolved inacetone or ethyl acetate portions with cellulose acetate or both is miscible in all proportions with cellu- The following is a specific example of the meth lose acetate that comprises heating an admixture 0d of producing the resinous product of the presof about 296 parts by weight of phthalic 40 ent invention: 296 parts, by weight, of phthalic dride and about parts of glycerme in an anhydride and 184 parts of giycerine are 'heated tight contafme? eqmpped with Sealed reflux conin a closed vessel which is equipped with a reflux delflser agltatmg the migtmie w reaches a condenser that in turn is sealed by a water seal fluid s.tate and then addmg lactlc acld as a or other means so that during the time of reacwlyzer m the proportion of {mm to t to tion no oxygen can reach the materials under 1 of glycerin? contmmqg heatmg of the treatment except the amount of oxygen that is in 3: 2:21 i giz g ga z i (glsmhngd T 1 2-; open the air space of the vessel and condenser. When The reaction predict 6? 3:33; 296 pallts by ed of lactic acid are added to act exclusively as a of glycenne heated m an an tight contamer catalyzin t Th equipped with a sealed reflux condenser to which g agen mass is heated for 2 hours is added when in fluid state lactic acid as a cataat a temperature not lngher than 160 C. and then iyzer in the proportion of from ,5 to ,5 mol. to is concentrated and distilled in an open vessel 1 mol. cf glycerine which mass has then been continuously heated, concentrated and distilled in an open vessel at not over 245 C. which product will about 2 parts of lactic acid as a catalyzer which.

mass has been continuously heated for about 2 hours at not higher than 160 C. and then concentrated and distilled in an open vessel at not over 245 C. which product will remain in solution with cellulosemcetate for the production of a stable and transparent fllm and is practically water white and when dissolved in acetone or ethyl acetate or both is miscible in all proportions with cellulose acetate. FELIX LAUTER. 

